1 . Field
Aspects of the present invention relate to a secondary battery having improved safety features.
2 . Description of the Related Art
As electronics and communications industries rapidly develop, the use of portable electronic devices such as camcorders, cellular phones, and notebook computers has increased. Accordingly, usage of secondary batteries has also been increased. These secondary batteries are used not only for portable electronic devices, but also for medium and larger-sized apparatuses such as an electric and electronic tools, automobiles, space transportation means and devices, motorbikes, motor scooters, and aerial transportation means and devices, which require high output and high power.
A high-power secondary battery using a non-aqueous electrolyte with high energy density has been developed. These high-power secondary batteries are typically large-capacity secondary batteries manufactured by connecting a plurality of secondary batteries in series for use in driving motors of devices requiring high power, e.g., electric vehicles, etc.
A large-capacity secondary battery generally includes a plurality of secondary batteries connected in series, and the shapes of each secondary battery may be cylindrical, square, and the like.
When a short circuit occurs inside a secondary battery or when a short circuit occurs due to an external foreign substance, overcurrent flows in the secondary battery. If the overcurrent continuously flows, excessive heat may be generated inside the secondary battery, possibly causing the secondary battery to explode or catch fire.